pH Checker Plus HI98100 Hanna Checker - Fresh & Marine Water

HI98100 pH Checker
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  • HI98100 pH Checker
  • HI98100 pH Checker
  • HI98100 pH Checker

pH Checker Plus HI98100 Hanna Checker - Fresh & Marine Water

67% Recommend this to a friend (4 of 6)

SKU: 209906

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Quick Overview

The most popular pH checker in the world has been giving consistent, reliable readings to over 1 million people. The HI98100 is very easy to calibrate to either one or two points with an extra large LCD readout, and single button operation makes this one of the best pH checkers on the market. The HI98100 also has a replaceable electrode making this the last pH checker you will ever need to buy.


Whats Included:

  • HI98100 pH Checker unit

  • HI1271 pH electrode

  • Plastic Carrying Case.

  • Hanna pH 4.01 Calibration Solution (2x)

  • Hanna pH 7.01 Calibration Solution (2x)

  • Hanna Electrode Cleaning Solution (2x)

  • instruction manual, instrument quality certificate and plastic carrying case.


Full Details

The pH in your tank is very easy to monitor and will tell you a lot about what is going on in your tank. If you need a pH checker for your main tank or just want to know what your water change water is, or really any liquid around the house this is the checker you have been waiting for.

The HI98100 Checker Plus pH testing unit has had a couple extra features added over the original model that everyone has grown to love while still retaining the same look and feel. With automatic calibration recognition, stability indicator, battery indicator, and auto-shut off the HI98100 is built to last a life time.


Single Button Operation - A single, large button will give you readings within seconds saving you valuable time.

Large LCD Readout - The large LCD screen makes reading measurements easier than ever with no guessing.

Automatic Calibration - The Checker Plus is calibrated automatically to one or two points. The calibration buffers are automatically recognized and after calibration the buffer values used are shown on the display as a tag.

Stability Indicator - The hour glass icon will indicate when a stable reading has been reached. Once the indicator disappears from the screen a stable reading has been reached and can then be recorded.

Automatic Shut-Off – The meter can be set to automatically turn off after 8 minutes or 60 minutes to conserve battery life in the event that the meter is left on. The auto off feature can be disabled.

Battery Life - The super long battery life will on average last close to 1000 hours. When the battery is running low and low battery indicator will illuminate on the LCD display. The battery is easly replaced on the back side of the checker.

pH Range - 0.00 to 14.00 pH
pH Resolution - 0.01 pH
pH Accuracy - ±0.2 pH
Calibration - Automatic, one or two points with three standard calibrations available (pH 4.01, 7.01 and 10.01)
Battery Type/Life - 1.5V CR2032 (1) / approximately 1000 hours of continuous use
Electrode/Probe - HI1271 pH electrode with screw type connector (included)
Environment - 0 to 50°C (32 to 122°F); RH max 95%
Dimensions - 50 x 174 x 21 mm (2 x 6.8 x 0.9”)
Weight - 50 g (1.8 oz.)


6 Items

  • Save your money By Reefer Teacher on 11/12/2017

    The checker is hard to use and the results are inconsistent.
  • Readings all over the map! By "It's so easy!", they said.. on 9/20/2017

    I was hoping this would make it easy to periodically check the accuracy of my Apex probe & determine if it needed to be re-calibrated. But honestly, after re-calibrating this thing several times (reads the calibrating fluid just fine) but still getting wildly swinging readings on the same sample of actual tank water, I have given up. I spent more time trying to get this thing to work than I ever would have just re-calibrating my Apex probe once a month.
  • Garbage! By Robert on 4/24/2017

    So I calibrate the meter using 7.01 and 4.01 solutions. You'd think if I put the meter backing the calibrating solution, I'd get a reading of 7.01 or 4.01... NOPE I got .6.98 or 7.3 of the other side I go id 4s. Don't get me wrong, every now and then it would read the correct value (like 1 put of 10 times). I was hoping this would be a quick and easy pH meter, but it isn't :(
  • Great checker By Rowan on 4/3/2017

    I bought this checker to make sure my Apex was accurate and it works great.
  • The jury is still out. I give it a yes but.... By Doc on 11/21/2016

    I purchased the Hanna Checker Plus to verify that water change water and the display tank water were close. I could not get the unit to work so I returned it. After doing some further reading of reviews on the the product I am willing to try another unit. Maybe I got a bad one or user error in calibration.
  • This PH checker is a must have! By Glen on 8/29/2016

    The Hanna PH checker is a must have item and is very easy to use. I have the API, ElOS, and Red Sea PH tests and they were not matching up at all. In fact the ELOS PH test was always at the same PH measurement, so I did not trust that anymore. Just remember to buy the storage solution for the Hanna PH checker when you buy the unit, because it does not come with it and you need it immediately after you use it. While I am at it, the Milwaukee MA887 Seawater Refractometer is also a must have item, because the Instant Ocean Hydrometer that I have is way off and I probably killed a few fish because of it.


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Product Questions

Is the accuracy really only +/-0.2??
I hoped this was a typo, and it is 0.02, but it says that on multiple sites. That's not really useful is it? That big of an error could cause some major panic and messing with chemistry thinking a tank was out of range when it was fine. Seems it is better to get a "close enough" result with hard to read colors from a kit than a +/-0.2 reading with a precision of 0.01. People confuse precision and accuracy.
Question by: Alex on Apr 12, 2016 4:31:00 PM
Great question!
That is in fact the accuracy listed by Hanna at being 0.2. I have included a direct link below as well.
Answer by: Connor (Admin) on Apr 18, 2016 6:18:00 PM
How often do you need to calibrate it?
Question by: Chris on Mar 9, 2016 12:18:00 PM
Great question!
This should be calibrated once a month to a minimum of once every 6 months. If accuracy is a concern you will want to calibrate more often to keep the system regular. Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Mar 9, 2016 12:33:00 PM
Does this checker come with a way to store it so that the bulb will not dry out. I will only be using it every couple of weeks to double check the reading on my Neptune Apex systems PH probe.
I seem to remember on one of your videos (which I love) that Ryan mentioned to keep the bulb of a PH probe wet. Thanks in advance for any advice and/or suggestions!
Alan Ray, Louisville, Ky.
Question by: Alan Ray Charles on Mar 25, 2016 10:45:00 AM
Great question!
This will come with a plastic cover for the probe tip and capable of holding solution for calibration. You are correct in saying the probe will ideally need to be kept in solution. If it is not you simply will need to re calibrate before use however these are designed to last quite a while while dry. Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Mar 28, 2016 10:45:00 AM